Fluid pressure engine starting system



sept. zo, 1960 D. w. ADAMS Em 2,953,127

FLUID PRESSURE ENGINE STARTING SYSTEM Filed April 8. 1959 2 Sheets-Sheet1 ENG/NE Q yl ,/q

efuarz co/vm 4m/f l ff t i cK /f Mineur aen/f n sua/.wwe i ./7 "5M/5 msssur v 4] IMLI/E5 Ms/NE A/Psz/PP/.Y

.Snom/6 A/x? Mame 5"'- A TTORNE Y Sept. 20, 1960 D. w. ADAMS ErAL.2,953,127

FLUID PRESSURE ENGINE STARTING SYSTEM Filed April 8, 1959 2 Sheets-Sheet2 7 i? INVENTORS if l BYW IIII @j MZ/ ATTORNEY United States Patent OFLUID PRESSURE ENGINE STARTING SYSTEM Donald W. Adams, Maple Heights,and Gerhard K.

Weber, Bay Village, Ohio, assignors to General Motors Corporation,Detroit, Mich., a corporation of Delaware v Filed Apr. 8, 1959, Ser. No.804,946

3 Claims. (Cl. 123-179) This invention relates generally to a fluidpressure actuating system, and more particularly to an engine startingsystem for an internal combustion engine including a luid pressureoperated starting device which is mounted on and adapted to selectivelydrive an internal combustion engine during its starting phase ofoperation.

Fluid pressure operated engine starting devices of the above-mentionedtype generally include a uid pressure motor and means for establishing adriving connection between the uid pressure starting motor and theilywheel ring gear of the associated engine. The driving connectionbetween the motor and the engine may be such as` to provide a continuoussolid drive between the two units. To prevent engine driving of thestarting motor during normal engine operation, however, a driveestablishing means is generally provided which is operable toselectively engage and disengage the driving connection. Such driveestablishing means generally comprises a clutch and/or a pinion gearwhich may be shifted axially into driving engagement with the iiywheelring gear of the associated engine. Drive establishing actuation of theclutch or shifting of the pinion gear may be effected manually orautomatically by initial rotation of the starting motor or by uidpressure means responsive to the supply of pressurized duid to thestarting motor. With uid pressure engine starting devices having eithercontinuous or selective drive means, the initial static frictional andinertial loads of the engine subject the starting drive connectionand'uid pressure starting motor to extreme load conditions. Ininstallations provided with selective drive establishing means, furtherdestructive load conditions may be imposed on the starter drive andmotor where the driving connection is not fully establishedV prior tothe full application of the supplied uid pressure to the starting motorsuch as occurs due to improper clutch or gear tooth engagement.

The invention contemplates an improved Huid pressure engine startingsystem including remote control valve mechanism operable to rst providea restricted iow of actuating pressure to the starter motor for thepurpose of establishing a proper driving connection between the starterdevice and the engine where selective drive means is provided, toinitially impose the static frictional and inertial loading of theengine on the starter drive |and motor under relatively low speed andtorque conditions and to thereafter provide for substantiallyunrestricted llow of pressurized uid to the starter motor through theoperation of a time delayed, pilot operatedmain controlvalve.

The foregoing Aand other objects, features and advantages of theinvention will become apparent from the following detailed descriptionof a preferred embodiment thereof in which reference is made lto theattached drawings, in which:

Figure 2 is an enlarged detail sectional view of the time delayed, pilotoperated control valve;

Figure 3 is a sectional view taken substantially in the plane of theline 3-3 in Figure 2; and

Figures 4 and 5 are sectional views showing different operativepositions of the remote control valve mechamsm. Y

Referring more particularly to Figure 1 of the drawings, the outline ofan internal combustion engine is indicated at 10. An engine starting airmotor 12 is mounted to one side of the engine ywheel housing -11 and ispreferably drivingly connectable to the engine ywheel ring gear(notrshown) by a suitable drive establishing means 13. The air motor 12is provided with an exhaust vent to atmosphere indicated at 14 and isconnectable through a main conduit 15, 15 to a suitable supply of highpressure air, such as an air pump charged reservoir. A main controlvalve 16 is interposed between main conduit portions 15 land 15 andserves to control the flow of pressurized air -to the starter motorthrough the main conduit. Operation of the main control valve 16 isreponsive to a pilot pressure signal which is sup plied thereto througha time delay metering valve 17. The main valve actuating pilot signal issupplied Ito the time delay metering valve through a branch line or con-Y duit 18 which intersects a conduit portion 19 of a conduit 19, 19 and19". The conduit 19, 19 and 19 is of restricted size and bypasses themain control valve. The flow of iluid pressure through the bypassconduit 19, 19' and 19"y is controlled by a three-way, open-end ventvalve 20 which may be mounted directly on the engine 'or may be locatedin a remote engine control station. Where the valve 20 is mounteddirectly on the engine, as shown, it may be manually operated locally ormay be operated remotely through suitable control linkages or cables,not shown. A check valve 21 mounted intermediate the conduit portions 19and 19" prevents reverse air now from the air motor and main conduitportion 15 toward the valve 20 and the pilot control branch conduit 18.

As best seen in Figure 2,7the main control valve 16 comprises a valvebody 22 which defines an inlet chamber 23 connected to the main airsupply conduit portion 15 and an outlet chamber 24 connected to the mainconduit portion 15 leading to the starter motor. A partition web 25separates the inlet and outlet' chambers 23 and 24V and has a port 26extending therethrough. Fluid ow through the port 26 is controlled by apop` pet valve member 27. The head portion 28 of the valve 27 isnormally biased toward port sealing engagement with the web 25 by aspring 29 which is compressively interposed between the valve head 28and a spring seating closure cap 30. The cap 30 is threadably mounted ina bore tapped in the valve body in axial alignment with the valvecontrolled port 26.l A valve actuating piston 31 of stepped diameter isthreadably mounted on the upper end of the valve stem of the poppetvalve member 27 which extends axially from the valve head through theport 26 and through the outlet chamber 24. The stepped diameter landsurfaces of the valve actuating piston 31 are slidably mounted and`O-ring sealed with respect to a bore and counterbore 32 and 33,respectively, formed in the valve body 22 in axial alignment with thevalve port 26.

The 4time delay metering valve 17 is combined with a check valve returnbypass and comprises a valve body member 34 which is secured to the mainvalve body 22, being sealed With respect thereto by an interposed gasket35. The metering valve body member is recessed at 36 `and deiinesranexpansible valve actuating chamber 36 with the valve actuating piston31. A drilled inlet pasand said first conduit means, said second valvemeans being operable when said second valve member is in its secondposition to Vent pressurized iiuid from said second conduit meansintermediate said second control Valve means and said first check valvemeans, a branch conduit means interconnecting said expansible chambermeans of said iirst valve to said second conduit means intermediate saidsecond control valve means and said first check valve means, a meteringvalve means operable to restrict the ilow of pressurized fluid in saidbranch conduit means to said expansible chamber means to delay actuationof said first valve member to its opened position, and a second checkvalve means bypassing said metering valve means and operable to permitunrestricted venting of said expansible chamber upon movement of saidsecond valve member to its vent position.

2. A fluid pressure engine starting system for an internal combustionengine including uid motor, means for establishing a driving connectionbetween said motor and the engine, a source of pressurized fluid, meansfor supplying pressurized uid from said source to said fluid motorincluding a first conduit means, a rst valve means operable to controlthe flow of pressurized uid through said irst conduit means andincluding a iirst valve member movable between a closed positionpreventing fluid ow through said rst conduit means and an openedposition permitting uid ow through said first conduit means, springmeans normally biasing said valve member toward its closed position, andexpausible chamber means associated with said valve member and operablein response to fluid pressure applied thereto to actuate said valvemember to its opened position, a second means for supplying pressurizedfluid from said source to said uid motor including a second conduitmeans of a size to permit only restricted ow of pressurized uid fromsaid pressurized fluid supply means to said iuid motor, a second valvemeans operable to control the ow of pressurized uid through said secondconduit means and including a second valve member movable between afirst position wherein restricted flow of pressurized uid to said Huidmotor is permitted and a second position Wherein pressurized fluid flowto said uid motor through said second conduit means is prevented, afirst check valve means in said second conduit means intermediate saidsecond valve means and said fluid motor for preventing reverse uid flowin said second conduit toward said pilot valve from said iiuid motor andsaid first conduit means, said second Valve means being operable whensaid second valve member is in its second position to vent said secondconduit means intermediate said second control valve means and saidiirst `check valve means, a branch conduit means interconnecting saidexpansible chamber means of said first valve means to said secondconduit means intermediate said second control Valve means and said irstcheck valve means, and ow control Valve means operable to restrict theilow of pressurized fluid through said branch conduit means to saidexpansible chamber means to delay actuation of said iirst valve memberto its opened position and to permit unrestricted venting of saidexpansible chamber upon movement of said second valve member to its ventposition.

3. A pneumatic engine starting system for an internal combustion engineincluding an air motor, means energizable to establish a drivingconnection between said motor and engine, a source of pressurized air, afirst means for supplying pressurized air from said source to said airmotor including a iirst conduit means, a rst valve means operable tocontrol the ow of pressurized air through said first conduit means andincluding a iirst valve member movable between a closed positionpreventing air flow through said rst conduit means and an openedposition permitting air flow through said rst conduit means, springmeans normally biasing said valve member toward its closed position, andan expansible chamber means associated with said valve member andoperable in response to air pressure applied thereto to actuate saidvalve member to its opened position, a second means for supplyingpressurized air from said source to said air motor including a secondconduit means of a size to provide restricted iiow of pressurized airfrom said source to said air motor, a second valve means operable tocontrol the ow of pressurized air through said second conduit means andincluding a second valve member movable between a first position whereinrestricted flow of pressurized air to said air motor' is permitted and asecond position wherein pressurized air flow to said motor through saidsecond conduit means is prevented, a first check valve means in saidsecond conduit means intermediate said second valve means and said airmotor for preventing reverse air flow in said second conduit meanstoward said second valve means from said air motor, said second valvemeans being operable when said second v-alve member is in its secondposition to vent said second conduit means intermediate said secondcontrol Valve means and said first check valve means to atmosphere, abranch conduit means interconnecting said expansible chamber means ofsaid irst valve to said second conduit means intermediate said secondcontrol valve means and said rst check valve means, a metering valvemeans operable to restrict the ilow of pressurized air through saidbranch conduit means to said expansible chamber means to delay actuationof said rst valve member to its opened position, and check valve meansbypassing said metering valve means and operable to permit unrestrictedventing of said expansible chamber upon movement of said second Valvemember to its Vent position.

References Cited in the le of this patent UNITED STATES PATENTS2,434,549 Cumming Ian. 13, 1948 2,449,889 Eisen Sept. 21, 1948 2,618,292Ring NOV. 18, 1952 2,802,452 Hogeman Aug. 13, 1957 2,847,984 GallantAug. 19, 1958

